Catheter having a tip with an elongated collar

ABSTRACT

A catheter having a tube and a tip connected to one end of the tube. The tip has a collar, an end member and lowered side walls positioned between the collar and the end member. The lowered side walls define an opening that is biased toward the end member.

PRIORITY CLAIM

This application is a continuation of and claims priority to and thebenefit of U.S. patent application Ser. No. 10/315,742, filed Dec. 9,2002, now U.S. Pat. No. 6,878,143, the disclosure of which isincorporated herein in its entirety, which is a continuation of U.S.patent application Ser. No. 09/614,360, filed Jul. 12, 2000, now U.S.Pat. No. 6,511,474.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is related to the following commonly owned co-pendingpatent applications: “Bolus for Non-Occluding High Flow Enteral FeedingTube,” Ser. No. 10/315,742, (Referenced Above); and “Bolus forNon-Occluding High Flow Enteral Feeding Tube,” Ser. No. 10/321,337.

TECHNICAL FIELD

The present invention generally relates to the irrigation,administration and aspiration of fluids to and from body cavities suchas the gastrointestinal tract through a catheter and, in particular, toan enteral feeding tube having a non-collapsible bolus containing afluid opening disposed at a distal end of the tube.

BACKGROUND OF THE INVENTION

Enteral nutrition is a form of hyperalimentation and metabolic supportin which nutrient formulas or medicaments are delivered directly to thegastrointestinal tract. Fluid administration and aspiration isaccomplished through use of a nasogastrointestinal tube generallyreferred to as an enteral feeding tube, as shown in FIG. 1. Enteralfeeding is frequently utilized where adequate nutritional intake cannotbe achieved through oral alimentation because of poor appetite, chronicnausea, general apathy, sedation or other symptoms or characteristicsassociated with serious disease. By delivering appropriate nutrientfluids directly to the gastrointestinal tract through an enteral feedingtube, nutritional and metabolic support of the patient is achievedwithout risk of sepsis or metabolic derangement, which may occur inintraveneous hyperalimentation. Because of increasing emphasis onout-patient care, enteral nutrition has been recognized as a desirablemethod of hyperalimentation as it requires only oral intubation of thefeeding tube rather than manipulation of sterile cannulae or other meansof interconnection with surgically implanted subclavian catheters asused in parenteral hyperalimentation.

Prior art feeding tubes, or catheters, typically include a rigid tip, orbolus, that includes a fluid outlet that promotes fluid flow. The fluidoutlet is typically provided through a sidewall of the bolus to guardagainst occlusion with mucous, gastrointestinal debris or coagulatedfeeding material. The bolus is also more rigid than the enteral tube sothat the tube can be easily guided during the intubation procedure. Theenteral tube may also be provided with a wire stylet within the tube toprovide more rigidity to the tube during intubation. The stylet can thenbe removed when the tube is inserted to the desired position within thegastrointestinal tract. Inadvertent exiting of the stylet duringintubation is reduced by positioning the fluid outlet within thesidewall of the bolus.

In some situations, the enteral tube is introduced into thegastrointestinal tract in an over-the-wire intubation procedure. Thisprocedure requires a bolus having an open ended tip. A wire stylet, orguide wire, extends through the enteral tube and out the open end of thebolus tip. The guide wire is used to guide the enteral tube and bolus toa location that may be more difficult to reach. The guide wire providesmore control over the tube and bolus for placement in these locations.For example, the guide wire may be used to guide the bolus and enteraltube through the stomach and into the jejunum or duodenum. The guidewire, which is relatively stiff compared to the enteral tube, isinserted ahead of the bolus to a desired position. The enteral tube isthen slipped over the wire and advanced to the desired position. Whenthe enteral tube is properly placed, the wire is removed.

One disadvantage in the prior art is that an over-the-wire intubationprocedure typically requires a bolus having a different design thanthose used in other procedures. Prior art boluses for use in anover-the-wire procedure are typically open-ended tubes that do notincorporate a rounded tip. On the other hand, boluses used in othertypes of intubation procedures typically have a rounded or bullet-shapedtip that provides less resistance during intubation. These shaped tipsalso reduce the risk of internal injury. Thus, each bolus designfacilitates the specific intubation procedure. Another disadvantage ofprior art boluses is their susceptibility to bending and kinking at acollar portion of the bolus that connects to a distal end of the enteraltube. Since the enteral tube is made of a material that is typicallymore flexible than the bolus, kinking readily occurs at the jointbetween the materials of differing flexibility. These boluses are alsosusceptible to bending at the fluid opening, where there is lessmaterial to provide rigidity to the bolus. This bending and kinkingmakes controlled intubation more difficult. Furthermore, the bending andkinking of the collar portion may also cause problems when using a wirestylet. The overall lengths of the stylet and tube are subject tocertain assembly tolerances. When the length of the stylet is within theshorter dimension range and the length of the tube is within the longerdimension range, the stylet may not reach the collar portion of thebolus. If the bolus is bent near the collar portion, the stylet maypierce the tube. On the other hand, if the length of the stylet iswithin the longer dimension range and the length of the tube is withinthe shorter dimension range, the stylet may be positioned within thefluid opening. In this situation, the stylet may pass through the fluidopening if the bolus is bent or kinked.

It is therefore an object of the present invention to provide a bolusfor an enteral feeding tube that provides delivery of fluid to a bodycavity or aspiration of a body cavity that does not become occluded withmucous, gastrointestinal debris and coagulated feeding material.

It is also an object of the present invention to provide a bolus for anenteral feeding tube that approximates the fluid flow ratecharacteristics of an open-ended tube.

It is also an object of the present invention to provide a bolus for anenteral feeding tube that has an elongated collar portion and a fluidoutlet that is biased toward the distal end of the bolus to allow forgreater tolerances between the lengths of the stylet and tube whilepreventing a shorter length stylet from piercing the tube or a longerlength stylet from passing through the fluid outlet if the bolus is bentor kinked.

It is also an object of the present invention to provide a single bolusthat can be used in more than one intubation procedure, including anover-the-wire procedure, by providing a stylet passage at the bolus tipwhile maintaining a generally contoured tip to promote travel throughtortuous anatomy.

These and other objects of the present invention will become readilyapparent after review of the specification and accompanying drawings.

SUMMARY OF THE INVENTION

The present invention is a bolus for an enteral feeding tube, orcatheter, that is capable of being used in an over-the-wire intubationprocedure as well as other intubation procedures. The bolus has agenerally tubular body defining a sidewall, a proximal end tube openingcapable of being connected to a distal end of the enteral feeding tube,and a generally rounded terminal end having a flattened tip. The bolusincludes a fluid opening within the sidewall of the bolus between theproximal end opening and the terminal end of the bolus. The fluidopening is biased toward the terminal end of the bolus thereby definingan elongated collar portion adjacent the proximal end tube opening ofthe bolus. The terminal end of the bolus has an aperture therethroughthat forms a stylet passage in communication with the fluid opening. Thestylet passage is sized to allow a stylet to pass therethrough when thetube is used in an over-the-wire intubation procedure.

The fluid opening includes a distal end and defines edge surfaces of theside wall of the bolus that converge and curve upwardly at the distalend of the opening near the terminal end of the bolus. Furthermore, aninterior surface of the sidewall opposite the fluid opening is curvedand slopes upwardly toward the distal end of the fluid opening. Thecurved interior surface and the fluid opening configuration allow forfluid flow that approximates the fluid flow rate characteristics of anopen-ended tube.

Additional features and advantages of the present invention aredescribed in, and will be apparent from, the following DetailedDescription of the Invention and the figures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is an illustration depicting an intubation configuration for anenteral feeding tube in a patient.

FIG. 2 is a plan view of a bolus of the present invention.

FIG. 3 is a cross-sectional view of the bolus depicted in FIG. 2 takenalong section line A—A.

FIG. 4 is a cross-sectional view of the bolus depicted in FIG. 2 takenalong section line A—A and depicting a range of curvatures of aninterior surface of the bolus opposite a fluid opening.

DETAILED DESCRIPTION OF THE INVENTION

While the present invention will be described fully hereinafter withreference to the accompanying drawings, in which a particular embodimentis shown, it is to be understood at the outset that persons skilled inthe art may modify the invention herein described while still achievingthe desired result of this invention. Accordingly, the description whichfollows is to be understood as a broad informative disclosure directedto persons skilled in the appropriate arts and not as limitations of thepresent invention.

It should also be understood that while the description is made hereinwith reference to an enteral feeding tube, this description is by way ofexample only. The principles of the present invention may be applied toall types of catheter tubes, including Foley catheters, urethralcatheters, and catheters for use in gastric, esophageal, pharyngeal,nasal, intestinal, rectalcolonic, choledochal, arterial, venous, cardiacand endobronchial applications.

Referring to FIGS. 1–3, the present invention is a bolus 10 adapted tobe connected to a distal end of an enteral feeding tube 11, as shown inFIG. 1. The bolus 10 can also be connected to the end of a catheter (notshown) for irrigation and aspiration of fluids within various bodycavities of a patient. The bolus 10 has a generally tubular, orcylindrical, body 12 having a center axis 14. The body 12 includes aproximal end 18 and a distal, or terminal, end 20. The terminal end 20is generally rounded and has a flattened tip configuration, as shown inFIGS. 2 and 3. The rounded configuration helps the bolus 10 to travelthrough tortuous anatomy, such as the gastrointestinal tract. The body12 also includes a fluid passage 22 disposed within the body 12. Thefluid passage 22 defines a bolus sidewall 24 and a proximal end tubeopening 26. The tube opening 26 is adapted to be connected to, and influid communication with, a distal end of the enteral feeding tube 11,as shown in FIG. 1.

The fluid passage 22 diverges from the center axis 14 of the body 12 todefine a fluid opening 28 through the sidewall 24, as shown in FIG. 3.The fluid opening 28 defines a proximal opening end 30, a distal openingend 32 and two generally vertical sidewalls 34 and 36 of the sidewall24. The sidewalls 34 and 36 have edge surfaces 38 and 40, respectively.The edge surfaces 38 and 40 converge and curve upwardly at the distalend 32 of the opening 28. The edge surfaces 38 and 40 also curveupwardly adjacent to the proximal opening end 30, as shown in FIG. 3. Aninterior surface 42 of the sidewall 24 opposite the fluid opening 28 iscurved and slopes upwardly toward the distal end 32 of the fluid opening28. The interior surface 42 and the curved edge surfaces 38 and 40 ofthe fluid opening 28 allows for fluid flow that approximates the fluidflow rate characteristics of an open-ended tube.

The fluid opening 28 is biased toward the distal end 20 of the body 12,thereby defining an elongated collar portion 44 near the proximal end 18of the body 12. The fluid opening also defines a distal end portion 46.The distal end 20 of the body 12 has an aperture 48 therethrough thatforms a stylet passage 50 through the distal end portion 46 incommunication with the fluid opening 28, as shown in FIG. 3. The styletpassage 50 is sized to allow a stylet (not shown) to pass therethroughwhen the tube is used in an over-the-wire intubation procedure. In apreferred embodiment, the stylet passage 50 has a diameter that isrelatively smaller than a diameter of the fluid passage 28. Thus, thedistal end portion 46 has a thicker material configuration than that ofthe sidewall 24 of the collar portion 44 of the body 12. The thickmaterial provides rigidity to the distal end 20 of the body 12 and helpsthe bolus to travel through the gastrointestinal tract during theintubation procedure.

The overall lengths of a wire stylet (not shown) and tube (not shown)are subject to certain assembly tolerances. The elongated collar portion44 and the forward-biased, or distal-biased, fluid opening 28effectively allow for increased tolerances between the length of a wirestylet disposed within the enteral tube of an enteral tube/styletassembly. The longer collar portion 44 creates a larger dimensionalrange in which a distal end of the wire stylet may be positioned whilenot falling short of the collar portion 44 or extending past the collarportion 44 and thereby residing within the fluid passage 22 at the fluidopening 28. The elongated collar portion 44 thereby prevents the styletfrom piercing the tube adjacent to the collar portion 44 if the bolus isbent or kinked. The collar portion 44 also prevents the stylet frompassing through the fluid opening 28 and potentially causing injury tothe patient during intubation.

The curved interior surface 42 is optimized to increase fluid flowthrough the fluid opening 28. FIG. 4 discloses a range of preferredcurvatures of the curved interior surface 42. The curvature of theinterior surface 36 is essentially a function of the inner diameter ofthe fluid passage 22 as characterized by a particular French size. TheFrench size scale is most commonly used to describe the size of medicaltubing such as enteral feeding tubing, urinary drainage tubing andcatheters. The French scale (hereinafter “Fr.”) is disclosed andcompared against the American and English medical tubing size scales inRemington's Pharmaceutical Sciences (6th Ed. 1980; Mack Publishing Co.)pp. 1906–1907. Generally, the enteral feeding tubing employed in thepresent invention have French sizes from five to ten Fr. and aregenerally from 15 to 42 inches in length depending on whether themedical application is for neonatal, juvenile or adult patients.

The upward curvature of the interior surface 42 cannot be too severeotherwise obstruction of the fluid stream will result causing fluidturbulence and decreasing fluid flow output. On the other hand, theupward curvature of the interior surface 42 cannot be too shallow so asto require an overly long bolus to accommodate the more gradual incline.

FIG. 4 discloses curvatures for the interior surface 42 that maximizefluid flow rates. The selected range of curvatures is defined by arcs(a) circumscribed from radii (r) having lengths of between and includingfive times and ten times an inner diameter of the fluid passage 22within the collar portion 44 and adjacent to the fluid opening 28, asindicated by the letter D in FIG. 4. In a preferred embodiment, theinner diameter D is equal to the inner diameter of the tubing. FIG. 4generally discloses one end of the general range of preferred curvaturesof the interior surface 42 in which an arc a′ is circumscribed from aradius r′ having a length equal to five times the inner diameter D. Atthe other end of the range of preferred curvatures, an arc a″ iscircumscribed from a radius r″ having a length equal to ten times theinner diameter D.

In specific embodiments of the present invention, a six French enteralfeeding tube having an inner diameter of about 0.055 inches requires theradius r defining the curvature of the interior surface 42 to have alength of about 0.489 inches or 8.890 times the inner diameter D. In anembodiment comprised of eight French enteral feeding tubing having aninner diameter of about 0.078 inches, the upward curvature of theinterior surface 42 is defined by an arc circumscribed from a radius rhaving a length of 0.525 inches or 6.730 times the inner diameter D. Inanother specific embodiment of the present invention utilizing tenFrench enteral tubing having an inner diameter of 0.100 inches, theinterior surface 42 was defined from an arc circumscribed from a radiushaving a length of 0.525 inches or 5.25 times the inner diameter D.

Another important feature of the present invention is the selectiverecessing or lowering of the height of the generally vertical side walls34 and 36 defined by the fluid opening 28. A transverse sectional heightis defined as the distance from an outside surface 52 of the sidewall 24of the bolus 10 directly opposite the fluid opening to the edge surfaces38 and 40. It has been found that the transverse sectional height of thevertical side walls 34 and 36 may range from a minimum height equal toone-half the inner diameter D. At a maximum, the transverse sectionalheight of the vertical side walls 34 and 36 should be no greater thanthe sum of the inner diameter D plus the thickness of the sidewall 24 ofthe bolus 10. The transverse sectional height may also be calculated interms of the inner diameter of the tubing. In a preferred embodiment,the inner diameter D is equal to the inner diameter of the tubing.Therefore, in a preferred embodiment of the present invention, thetransverse sectional height of the vertical side walls 34 and 36 isequal to about the inner diameter of the tubing.

If the transverse sectional height of the vertical side walls 34 and 36is less than one half the inner diameter of the tubing, then bolus 10has an increased tendency to kink or bend. On the other hand, if thevertical side walls 34 and 36 have a transverse sectional height greaterthan the sum of the inner diameter and thickness of the sidewall 22,this results in a vertical side wall height exceeding the outerconfiguration of bolus 10 thereby creating difficulty in intubation.Thus, the vertical side walls 34 and 36 are dimensioned to minimizekinking, bending, and occlusion of the fluid opening while maximizingfluid flow through the fluid opening. The present invention provides aversatile bolus for an enteral feeding tube, or catheter, that iscapable of being used in an over-the-wire intubation procedure inaddition to other intubation procedures. The bolus provides a styletpassage in combination with a generally rounded distal end having ablunt tip. The stylet passage allows the bolus to be used for anover-the-wire intubation procedure and the blunt tip allows the bolus tobe inserted in an intubation procedure while maintaining minimalresistance and minimizing occlusion of the fluid opening.

While the specific embodiments have been illustrated and described,numerous modifications come to mind without significantly departing fromthe spirit of the invention and the scope of protection is only limitedby the scope of the accompanying claims.

It should be understood that various changes and modifications to thepresently preferred embodiments described herein will be apparent tothose skilled in the art. Such changes and modifications can be madewithout departing from the spirit and scope of the present invention andwithout diminishing its intended advantages. It is therefore intendedthat such changes and modifications be covered by the appended claims.

1. A catheter comprising: a tube having a plurality of ends; and a tippositionable within a bodily cavity, the tip having: (a) a collar memberthat defines an opening, the collar member having: (i) a length; (ii) afirst end and a second end, the first end connected to one of the endsof the tube; and (iii) a bottom wall, a top wall and a plurality of sidewalls positioned between the first and second ends, the side wallsconnecting the top wall to the bottom wall; (b) an end member having:(i) a length that is less than the length of the collar member; (ii) afirst end and a second end; and (iii) a bottom wall, a top wall and aplurality of side walls positioned between said first and second ends,said side walls connecting said top wall to the bottom wall of the endmember; and (c) an intermediate section positioned between the collarmember and end member, the intermediate section including another bottomwall and a plurality of lowered side walls, said another bottom wall andthe lowered side walls being connected to the collar member and the endmember, a portion of the lowered side walls and a portion of the topwalls of both the collar member and the end member defining anotheropening having a center, the center of said opening positioned closer tothe first end of the end member than the second end of the collarmember.
 2. The catheter of claim 1, wherein the second end of the endmember has a partially rounded shape.
 3. The catheter of claim 1,wherein the opening positioned between the second end of the collarmember and the first end of the end member has an elongated shape. 4.The catheter of claim 1, wherein a portion of the bottom wall of theintermediate section has a sloped interior surface.
 5. The catheter ofclaim 1, wherein a portion of the bottom wall of the intermediatesection has an arc-shaped interior surface.
 6. The catheter of claim 5,wherein: (a) the opening of the first end of the collar member has aninner diameter; and (b) said arc-shaped interior surface is defined by aradius, the radius having a magnitude within a range between andincluding five times and ten times said inner diameter.
 7. The catheterof claim 1, wherein: (a) the opening of the first end of the collarmember has an inner diameter; and (b) each of the lowered side walls ofthe intermediate section has a height that is selected from the groupconsisting of: (i) a height substantially equal to one-half of saidinner diameter; (ii) a height equal to one-half of said inner diameter;and (iii) a height having a magnitude within a range between andincluding one-half of said inner diameter and said inner diameter. 8.The catheter of claim 1, wherein: (a) the tube has an inner diameter;and (b) each of the lowered side walls of the intermediate section has aheight that is selected from the group consisting of: (i) a heightsubstantially equal to one-half of said inner diameter; (ii) a heightequal to one-half of said inner diameter; and (iii) a height having amagnitude within a range between and including one-half of said innerdiameter and said inner diameter.
 9. The catheter of claim 1, whereinthe second end of the end member defines an opening sized to receive awire.
 10. A catheter comprising: a tube having a plurality of ends; anda tip having: (a) a collar member that defines an opening, the collarmember having: (i) a length; (ii) a first end and a second end, thefirst end connected to one of the ends of the tube; and (iii) a bottomwall, a top wall and a plurality of side walls positioned between thefirst and second ends, the side walls connecting the top wall to thebottom wall; (b) an end member having: (i) a length that is less thanthe length of the collar member; (ii) a first end and a second end; and(iii) a bottom wall, a top wall and a plurality of side walls positionedbetween said first and second ends, said side walls connecting said topwall to the bottom wall of the end member; and (c) an intermediatesection positioned between the collar member and the end member, theintermediate section including another bottom wall and a plurality oflowered side walls, said another bottom wall and the lowered side wallsbeing connected to the collar member and the end member, a portion ofthe lowered side walls and a portion of the top walls of both the collarand the end member defining another opening having a center, the centerof said opening being positioned closer to the first end of the endmember than the second end of the collar member.
 11. The catheter ofclaim 10, wherein the second end of the end member has a partiallyrounded shape.
 12. The catheter of claim 10, wherein the openingpositioned within the intermediate section has an elongated shape. 13.The catheter of claim 10, wherein a portion of the bottom wall of theintermediate section has a sloped interior surface.
 14. The catheter ofclaim 10, wherein a portion of the bottom wall of the intermediatesection has an arc-shaped interior surface.
 15. The catheter of claim14, wherein: (a) the opening of the first end of the collar member hasan inner diameter; and (b) said arc-shaped interior surface is definedby a radius, the radius having a magnitude within a range between andincluding five times and ten times said inner diameter.
 16. The catheterof claim 10, wherein: (a) the opening of the first end of the collarmember has an inner diameter; and (b) each of the lowered side walls ofthe intermediate section has a height that is selected from the groupconsisting of: (i) a height substantially equal to one-half of saidinner diameter; (ii) a height equal to one-half of said inner diameter;and (iii) a height having a magnitude within a range between andincluding one-half of said inner diameter and said inner diameter. 17.The catheter of claim 10, wherein: (a) the tube has an inner diameter;and (b) each of the lowered side walls of the intermediate section has aheight that is selected from the group consisting of: (i) a heightsubstantially equal to one-half of said inner diameter; (ii) a heightequal to one-half of said inner diameter; and (iii) a height having amagnitude within a range between and including one-half of said innerdiameter and said inner diameter.
 18. The catheter of claim 10, whereinthe second end of the end member defines an opening sized to receive awire.
 19. A catheter comprising: a tube having a plurality of ends; anda tip positionable within a bodily cavity, the tip having: (a) a collarmember that defines an opening, the collar member having: (i) a length;(ii) a first end and a second end, the first end connected to one of theends of the tube; and (iii) a bottom wall, a top wall and a plurality ofside walls positioned between the first and second ends, the side wallsconnecting the top wall to the bottom wall; (b) an end member having:(i) a length that is less than the length of the collar member; (ii) afirst end and a second end, the second end having a partially roundedshape; and (iii) a bottom wall, a top wall and a plurality of side wallspositioned between said first and second ends, said side wallsconnecting said top wall to the bottom wall of the end member; and (c)an intermediate section positioned between the collar member and endmember, the intermediate section including another bottom wall and aplurality of lowered side walls, said another bottom wall and thelowered side walls being connected to the collar member and the endmember, a portion of the lowered side walls and a portion of the topwalls of both the collar member and the end member defining anotheropening, said opening having a center and an elongated shape, the centerof said opening being positioned closer to the first end of the endmember than the second end of the collar member.
 20. The catheter ofclaim 19, wherein a portion of the bottom wall of the intermediatesection has an arc-shaped interior surface.
 21. The catheter of claim20, wherein: (a) the opening of the first end of the collar member hasan inner diameter; and (b) said arc-shaped interior surface is definedby a radius, the radius having a magnitude within a range between andincluding five times and ten times said inner diameter.
 22. The catheterof claim 19, wherein: (a) the opening of the first end of the collarmember has an inner diameter; and (b) each of the lowered side walls ofthe intermediate section has a height that is selected from the groupconsisting of: (i) a height substantially equal to one-half of saidinner diameter; (ii) a height equal to one-half of said inner diameter;and (iii) a height having a magnitude within a range between andincluding one-half of said inner diameter and said inner diameter. 23.The catheter of claim 19, wherein: (a) the tube has a designated innerdiameter; and (b) each of the lowered side walls of the intermediatesection has a height that is selected from the group consisting of: (i)a height substantially equal to one-half of said inner diameter; (ii) aheight equal to one-half of said inner diameter; and (iii) a heighthaving a magnitude within a range between and including one-half of saidinner diameter and said inner diameter.
 24. The catheter of claim 19,wherein the second end of the end member defines an opening sized toreceive a wire.